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Peter Koehler - One of the best experts on this subject based on the ideXlab platform.
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Comparative Study on Gluten Protein Composition of Ancient (Einkorn, Emmer and Spelt) and Modern Wheat Species (Durum and Common Wheat)
Foods (Basel Switzerland), 2019Co-Authors: Sabrina Geisslitz, Katharina Anne Scherf, C. Friedrich H. Longin, Peter KoehlerAbstract:The spectrophotometric Bradford assay was adapted for the analysis of gluten protein contents (gliadins and Glutenins) of spelt, durum wheat, emmer and einkorn. The assay was applied to a set of 300 samples, including 15 cultivars each of common wheat, spelt, durum wheat, emmer and einkorn cultivated at four locations in Germany in the same year. The total protein content was equally influenced by location and wheat species, however, gliadin, Glutenin and gluten contents were influenced more strongly by wheat species than location. Einkorn, emmer and spelt had higher protein and gluten contents than common wheat at all four locations. However, common wheat had higher Glutenin contents than einkorn, emmer and spelt resulting in increasing ratios of gliadins to Glutenins from common wheat (< 3.8) to spelt, emmer and einkorn (up to 12.1). With the knowledge that Glutenin contents are suitable predictors for high baking volume, cultivars of einkorn, emmer and spelt with good predicted baking performance were identified. Finally, spelt, emmer and einkorn were found to have a higher nitrogen partial factor productivity than common and durum wheat making them promising crops for a more sustainable agriculture.
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gluten protein composition and aggregation properties as predictors for bread volume of common wheat spelt durum wheat emmer and einkorn
Journal of Cereal Science, 2018Co-Authors: Sabrina Geisslitz, Katharina Anne Scherf, Herbert Wieser, Peter KoehlerAbstract:Abstract The technological properties of the ancient wheat species spelt, emmer and einkorn are considered inferior compared to common wheat and durum wheat, but there are only few comparative studies between ancient and modern wheat species. To help fill this gap, protein content and composition, gluten aggregation, dough and bread properties were determined in a unique set of eight cultivars each of common wheat, spelt, durum wheat, emmer and einkorn grown under standardized conditions at one location in the same year. Spearman correlations and principal component analysis (PCA) revealed that especially the contents of Glutenins, high-molecular-weight Glutenin subunits and Glutenin macropolymer were suitable to predict the volume of breads made from wholemeal flours of the five wheat species using microbaking tests. Based on their proximity to common wheat in the PCA, one cultivar each of spelt, emmer and einkorn was identified that had similar protein analytical, functional and baking properties to common wheat. Furthermore, the characterization of gluten aggregation behavior using the GlutoPeak test (GPT) enabled an estimation of dough properties and bread volume. Therefore, the fast and easy GPT may serve as an alternative to time-consuming and labor-intensive baking tests.
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Effects of thermal and mechanical treatments on the physicochemical properties of wheat flour
European Food Research and Technology, 2018Co-Authors: Claudia Vogel, Katharina Anne Scherf, Peter KoehlerAbstract:Planetary ball milling is a possible way to improve the technological properties of wheat flour by thermal and mechanical modifications. In the present study, roller milled common wheat flours (Triticum aestivum L.) were additionally modified in a ball mill by varying mill parameters such as rotation speed and grinding time. As a result of ball milling, the flours experienced temperatures of up to 100 °C, the range of particle sizes strongly increased as well as the content of damaged starch. The treated flours were also analyzed for the protein distribution by SDS-polyacrylamide-gel electrophoresis and proteins were quantitated by an extraction/high-performance liquid chromatography (Osborne fractionation) and an extraction/gel permeation chromatography procedure (SDSL/GMP fractionation). Intense mechanical/thermal treatment led to a decrease of the content of extractable protein and shifted ethanol-soluble gliadins to the Glutenin fraction. Cysteine-containing alpha- and gamma-gliadins initially soluble in 60% ethanol were bound to ethanol-insoluble Glutenins by thiol–disulfide interchange reactions. Linked to that, a high level of modification also significantly decreased the gliadin/Glutenin ratio and increased the Glutenin macropolymer content. Cysteine-free omega5- and omega1,2-gliadin types were only weakly affected by milling. Heating induced by mechanical treatment is supposed to be mainly responsible for these effects. Thiol–disulfide interchange can also explain the increase of the particle size after intense ball milling, because flour particles could stick together via disulfide bonds between proteins located on the surface of different particles.
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SDS-PAGE of flours, prolamin and glutelin fractions and isolated gluten protein types.
2017Co-Authors: Kathrin Schalk, Peter Koehler, Barbara Lexhaller, Katharina Anne ScherfAbstract:(A) Wheat. M: marker, 1: wheat flour, 2: wheat prolamin fraction, 3: ω5-gliadins, 4: ω1,2-gliadins, 5: α-gliadins, 6: γ-gliadins, 7: wheat glutelin fraction, 8: high-molecular-weight Glutenin subunits (HMW-GS), 9: low-molecular-weight Glutenin subunits (LMW-GS). (B) Rye. M: marker, 10: rye flour, 11: rye prolamin fraction, 12: ω-secalins, 13: γ-75k-secalins, 14: γ-40k-secalins, 15: rye glutelin fraction, 16: HMW-secalins. (C) Barley. M: marker, 17: barley flour, 18: barley prolamin fraction, 19: γ/B-hordeins, 20: C-hordeins, 21: barley glutelins, 22: B/γ-hordeins, 23: D-hordeins. (D) Oats. 24: oat prolamin fraction (avenins), 25: oat flour.
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improved quantitation of gluten in wheat starch for celiac disease patients by gel permeation high performance liquid chromatography with fluorescence detection gp hplc fld
Journal of Agricultural and Food Chemistry, 2016Co-Authors: Katharina Anne Scherf, Herbert Wieser, Peter KoehlerAbstract:Purified wheat starch (WSt) is commonly used in gluten-free products for celiac disease (CD) patients. It is mostly well-tolerated, but doubts about its safety for CD patients persist. One reason may be that most ELISA kits primarily recognize the alcohol-soluble gliadin fraction of gluten, but insufficiently target the alcohol-insoluble Glutenin fraction. To address this problem, a new sensitive method based on the sequential extraction of gliadins, Glutenins, and gluten from WSt followed by gel-permeation high-performance liquid chromatography with fluorescence detection (GP-HPLC-FLD) was developed. It revealed that considerable amounts of Glutenins were present in most WSt. The gluten contents quantitated by GP-HPLC-FLD as sum of gliadins and Glutenins were higher than those by R5 ELISA (gluten as gliadin content multiplied by a factor of 2) in 19 out of 26 WSt. Despite its limited selectivity, GP-HPLC-FLD may be applied as confirmatory method to ELISA to quantitate gluten in WSt.
Herbert Wieser - One of the best experts on this subject based on the ideXlab platform.
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gluten protein composition and aggregation properties as predictors for bread volume of common wheat spelt durum wheat emmer and einkorn
Journal of Cereal Science, 2018Co-Authors: Sabrina Geisslitz, Katharina Anne Scherf, Herbert Wieser, Peter KoehlerAbstract:Abstract The technological properties of the ancient wheat species spelt, emmer and einkorn are considered inferior compared to common wheat and durum wheat, but there are only few comparative studies between ancient and modern wheat species. To help fill this gap, protein content and composition, gluten aggregation, dough and bread properties were determined in a unique set of eight cultivars each of common wheat, spelt, durum wheat, emmer and einkorn grown under standardized conditions at one location in the same year. Spearman correlations and principal component analysis (PCA) revealed that especially the contents of Glutenins, high-molecular-weight Glutenin subunits and Glutenin macropolymer were suitable to predict the volume of breads made from wholemeal flours of the five wheat species using microbaking tests. Based on their proximity to common wheat in the PCA, one cultivar each of spelt, emmer and einkorn was identified that had similar protein analytical, functional and baking properties to common wheat. Furthermore, the characterization of gluten aggregation behavior using the GlutoPeak test (GPT) enabled an estimation of dough properties and bread volume. Therefore, the fast and easy GPT may serve as an alternative to time-consuming and labor-intensive baking tests.
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improved quantitation of gluten in wheat starch for celiac disease patients by gel permeation high performance liquid chromatography with fluorescence detection gp hplc fld
Journal of Agricultural and Food Chemistry, 2016Co-Authors: Katharina Anne Scherf, Herbert Wieser, Peter KoehlerAbstract:Purified wheat starch (WSt) is commonly used in gluten-free products for celiac disease (CD) patients. It is mostly well-tolerated, but doubts about its safety for CD patients persist. One reason may be that most ELISA kits primarily recognize the alcohol-soluble gliadin fraction of gluten, but insufficiently target the alcohol-insoluble Glutenin fraction. To address this problem, a new sensitive method based on the sequential extraction of gliadins, Glutenins, and gluten from WSt followed by gel-permeation high-performance liquid chromatography with fluorescence detection (GP-HPLC-FLD) was developed. It revealed that considerable amounts of Glutenins were present in most WSt. The gluten contents quantitated by GP-HPLC-FLD as sum of gliadins and Glutenins were higher than those by R5 ELISA (gluten as gliadin content multiplied by a factor of 2) in 19 out of 26 WSt. Despite its limited selectivity, GP-HPLC-FLD may be applied as confirmatory method to ELISA to quantitate gluten in WSt.
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The influence of Fusarium infection and growing location on the quantitative protein composition of (part I) emmer (Triticum dicoccum)
European Food Research and Technology, 2010Co-Authors: Kai Eggert, Herbert Wieser, Elke PawelzikAbstract:The effect of the fungal infection by Fusarium graminearum and Fusarium culmorum of emmer and wheat cultivars on their total protein content and the protein fractions albumins + globulins, gliadins and Glutenins and their different protein types was investigated. In addition, the influence of two different locations on the quantitative protein composition was evaluated. The results showed that Fusarium infection changed the content of gliadins and Glutenins in emmer and wheat. The wheat Glutenin fractions and types were found to be more strongly affected by the Fusarium spp. infection than the Glutenin fractions and types in emmer cultivars in spite of the wheat’s lower degree of infection. The nitrogen supply at the two locations was associated with an increase in the gliadin content in emmer and an increase in the Glutenin content in emmer and wheat. Nitrogen availability, a factor which promotes gene expression, resulted here in a species-specific effect on the gliadin/Glutenin ratio.
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changes of folates dietary fiber and proteins in wheat as affected by germination
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Peter Koehler, Herbert Wieser, Georg Hartmann, Michael RychlikAbstract:Wheat kernels of the cultivar ‘Tommi' were germinated for up to 168 h at 15, 20, 25, or 30 °C. Samples were taken at different stages of germination and were analyzed for the quantitative protein composition using an extraction/HPLC method, for folate vitamers using a stable isotope dilution assay, and for soluble, insoluble, and total dietary fiber using a gravimetric method. Gluten proteins were substantially degraded during germination. During the first stages of germination the degradation of Glutenins was predominant, whereas longer germination times were required to degrade gliadins. The optimal temperature for gliadin degradation was 20 °C, and that for Glutenin degradation was 25 °C. ω5- and ω1,2-gliadins were less sensitive to proteolytic degradation than α- and γ-gliadins, and LMW subunits of Glutenin were less sensitive than HMW subunits. During germination a time- and temperature-dependent increase of total folate occurred. A maximum 3.6-fold concentration was obtained after 102 h of germinati...
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chemistry of gluten proteins
Food Microbiology, 2007Co-Authors: Herbert WieserAbstract:Gluten proteins play a key role in determining the unique baking quality of wheat by conferring water absorption capacity, cohesivity, viscosity and elasticity on dough. Gluten proteins can be divided into two main fractions according to their solubility in aqueous alcohols: the soluble gliadins and the insoluble Glutenins. Both fractions consist of numerous, partially closely related protein components characterized by high glutamine and proline contents. Gliadins are mainly monomeric proteins with molecular weights (MWs) around 28,000-55,000 and can be classified according to their different primary structures into the alpha/beta-, gamma- and omega-type. Disulphide bonds are either absent or present as intrachain crosslinks. The Glutenin fraction comprises aggregated proteins linked by interchain disulphide bonds; they have a varying size ranging from about 500,000 to more than 10 million. After reduction of disulphide bonds, the resulting Glutenin subunits show a solubility in aqueous alcohols similar to gliadins. Based on primary structure, Glutenin subunits have been divided into the high-molecular-weight (HMW) subunits (MW=67,000-88,000) and low-molecular-weight (LMW) subunits (MW=32,000-35,000). Each gluten protein type consists or two or three different structural domains; one of them contains unique repetitive sequences rich in glutamine and proline. Native Glutenins are composed of a backbone formed by HMW subunit polymers and of LMW subunit polymers branched off from HMW subunits. Non-covalent bonds such as hydrogen bonds, ionic bonds and hydrophobic bonds are important for the aggregation of gliadins and Glutenins and implicate structure and physical properties of dough.
D Kneževic - One of the best experts on this subject based on the ideXlab platform.
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the influence of changes in gluten complex structure on technological quality of wheat triticum aestivum l
Food Research International, 2007Co-Authors: Aleksandra Torbica, M Antov, Jasna Mastilovic, D KneževicAbstract:The influence of changes in Glutenin-gliadin complex of grain on technological quality of the wheat variety (Triticum aestivum L.) was studied. It was shown that wheat-bug attack caused differences in electrophoregram pattern of Glutenins and gliadins concerning their number, intensities and molecular weights. The environmental influence had detrimental effect on rheological properties of dough. Expected heat-stress effect - the increase of gliadin-Glutenin ratio was not detected. The modified method for gluten index was introduced and it was proven as superior to the standard method in predicting technological quality of wheat.
C P Sandiford - One of the best experts on this subject based on the ideXlab platform.
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identification of the major water salt insoluble wheat proteins involved in cereal hypersensitivity
Clinical & Experimental Allergy, 1997Co-Authors: C P Sandiford, A S Tatham, Roger J Fido, J A Welch, M Jones, R D Tee, P R Shewry, A Newman J TaylorAbstract:BACKGROUND Several studies have investigated water/salt soluble proteins which comprise 50% of the proteins in wheat. The remaining 50% of wheat proteins, are water/salt insoluble proteins of which there is limited information on their role in cereal hypersensitivity. OBJECTIVES To investigate the allergenicity of the water/salt insoluble gliadin and Glutenin proteins (prolamins). METHODS RAST, electrophoresis and Western blotting were used to identify water/salt insoluble wheat allergens. Competitive RAST inhibition was conducted to investigate cross-reactivity between prolamins and water/salt soluble wheat proteins. RESULTS Specific IgE to alpha-gliadin and to total Glutenins were detected in all sera. IgE to beta-, gamma-, fast omega-, and slow omega-gliadin were present in lower numbers of sera. Prolamin allergens of 90-11 kDa were identified by immunoblotting. Water/salt soluble proteins crossreacted with alpha-gliadin and total Glutenins. CONCLUSIONS Individuals who are hypersensitive to water/salt soluble wheat proteins produce specific IgE to water/salt insoluble wheat proteins. Western blotting has shown that gliadins, Glutenins and proteins with similar molecular weights as the endogenous water/salt soluble wheat enzyme inhibitors are important allergens. Alpha and fast omega- are the most allergenic gliadins. The water/salt insoluble proteins share cross-reacting epitopes with water/salt soluble proteins. These data show that the numbers of proteins involved in the development of cereal hypersensitivity is greater than previously believed and that the development of specific IgE to alpha-gliadin may in part depend on the presence of cross-reacting antibodies to water/salt soluble flour allergens.
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Identification of the major water/salt insoluble wheat proteins involved in cereal hypersensitivity
Clinical Experimental Allergy, 1997Co-Authors: C P Sandiford, A S Tatham, Roger J Fido, J A Welch, M Jones, R D Tee, P R Shewry, A. J. Newman TaylorAbstract:BACKGROUND Several studies have investigated water/salt soluble proteins which comprise 50% of the proteins in wheat. The remaining 50% of wheat proteins, are water/salt insoluble proteins of which there is limited information on their role in cereal hypersensitivity. OBJECTIVES To investigate the allergenicity of the water/salt insoluble gliadin and Glutenin proteins (prolamins). METHODS RAST, electrophoresis and Western blotting were used to identify water/salt insoluble wheat allergens. Competitive RAST inhibition was conducted to investigate cross-reactivity between prolamins and water/salt soluble wheat proteins. RESULTS Specific IgE to alpha-gliadin and to total Glutenins were detected in all sera. IgE to beta-, gamma-, fast omega-, and slow omega-gliadin were present in lower numbers of sera. Prolamin allergens of 90-11 kDa were identified by immunoblotting. Water/salt soluble proteins crossreacted with alpha-gliadin and total Glutenins. CONCLUSIONS Individuals who are hypersensitive to water/salt soluble wheat proteins produce specific IgE to water/salt insoluble wheat proteins. Western blotting has shown that gliadins, Glutenins and proteins with similar molecular weights as the endogenous water/salt soluble wheat enzyme inhibitors are important allergens. Alpha and fast omega- are the most allergenic gliadins. The water/salt insoluble proteins share cross-reacting epitopes with water/salt soluble proteins. These data show that the numbers of proteins involved in the development of cereal hypersensitivity is greater than previously believed and that the development of specific IgE to alpha-gliadin may in part depend on the presence of cross-reacting antibodies to water/salt soluble flour allergens.
Pierre Briozzo - One of the best experts on this subject based on the ideXlab platform.
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A Recombinant omega-Gliadin-like D-Type Glutenin and an alpha-Gliadin from Wheat (Triticum aestivum): Two Immunoglobulin E Binding Proteins, Useful for the Diagnosis of Wheat-Dependent Allergies
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Hamza Mameri, Sandra Denery-papini, C. Pecquet, I. Bouchez-mahiout, D. Choudat, N. Raison-peyron, Habib Chabane, Stephane Kerre, Yann Gohon, Pierre BriozzoAbstract:Among the wheat prolamins, D-type Glutenins display a highly repetitive sequence similar to omega-gliadins, but they contain a cysteine, that allows them to be included in the gluten macropolymers. An omega-gliadin-like D-type Glutenin, an alpha-gliadin, and an omega 5-gliadin-like D-type Glutenin were obtained as recombinant proteins and compared using synchrotron radiation circular dichroism. This technique evidenced the strong thermostability of the omega 5-gliadin-like protein. The IgE reactivity of recombinant proteins was evaluated using 45 sera from wheat-allergic patients. The sera from patients diagnosed with cutaneous hypersensitivity to hydrolyzed wheat proteins often reacted with the omega-gliadin-like D-type Glutenin and alpha-gliadin, whereas the IgE reaction was less frequent after dietary sensitization. So, these two proteins could be useful to diagnose these diseases. The sera from patients with exercise-induced anaphylaxis recognized the omega 5-gliadin-like protein as a positive control and, less frequently, the other proteins tested. Only some sera from patients with baker's asthma reacted with the proteins tested.
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Immunoglobulin-E Reactivity and Structural Analysis of Wheat Low-Molecular-Weight Glutenin Subunits and Their Repetitive and Nonrepetitive Halves
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Hamza Mameri, Sandra Denery-papini, C. Pecquet, D. Choudat, N. Raison-peyron, Yann Gohon, Jacques Snegaroff, Frank Wien, Pierre BriozzoAbstract:The IgE reactivity of the recombinant Glutenin subunits P73 and B16, and of their repetitive N-terminal and nonrepetitive C-terminal halves, was analyzed using dot-blot with sera from patients diagnosed with baker's asthma, wheat-dependent exercise-induced anaphylaxis, or allergy to hydrolyzed wheat proteins. The linear epitopes of B16 were identified using the Pepscan method. Except for one common epitope, the IgE binding domains of Glutenins differ from those of omega 5-gliadins. Secondary structure content of the proteins was determined using synchrotron radiation circular dichroism (SRCD): while a structures were predominant in all Glutenin subunits, fragments, or chimeras, a high IgE reactivity was associated with proteins rich in beta structures. Mixing B16 halves induced conformational interaction, as evidenced by dynamic light scattering and SRCD. IgE reactivity was correlatively increased, as when the halves were associated in the B16 P73 chimera. These results suggest that structural interaction between N- and C-terminal halves may promote epitope presentation.